1. Field of the Invention
This invention relates to a device for raising and lowering a step provided at one end of a vertically movable table in a transfer lift rotatably between its substantially vertical position and its substantially horizontal position in which it forms an extension of the table when the lift is used for transferring a container, bogie, wheelchair, etc. from one place to another having a higher or lower level of height, as between a platform and the bed of a truck, or between a road or ground floor and a raised floor in a building.
2. Description of the Prior Art
There is known a transfer lift having a rotatable transfer step as hereinabove described. Reference is made to FIG. 9 showing a part of a typical known lift of the type to which this invention pertains. A post 26 is upstanding from the lift adjacent to the transfer step 23 and a handlebar 32 is rotatably attached to the post 26. A connecting rod 30 is rotatably connected between the step 23 and the handlebar 32. The step 23 can be raised or lowered if the handlebar 32 is raised or lowered, as shown by broken and solid lines in FIG. 9.
When the lift is used to transfer a container by way of example, the container is moved onto a table past the loading end of the lift, while the transfer step is kept in its raised position. The transfer step in its raised position serves as a stopper for preventing the container from moving past the unloading end of the lift at which the transfer step is located. The table is, for example, raised to an appropriate height and the transfer step is, then, lowered to permit the transfer of the container. However, as the handlebar is situated near the transfer step, i.e. near the unloading end of the lift, the operator of the lift who has caused the container to be received onto the table is required to go from its loading end to its unloading end to operate the handlebar. Moreover, when the container is moved onto the table, it is likely to force the transfer step into its lowered position and if the table is raised with the transfer step in its lowered position, there is every likelihood that the container may fall down.